A Practical Limit of Security Proof in the Ideal Cipher Model : Possibility of Using the Constant As a Trapdoor In Several Double Block Length Hash Functions

Donghoon Chang

Paper 2006/481

A Practical Limit of Security Proof in the Ideal Cipher Model : Possibility of Using the Constant As a Trapdoor In Several Double Block Length Hash Functions

Donghoon Chang

Abstract

Recently, Shoichi Hirose \cite{Hirose06} proposed several double block length (DBL) hash functions. Each DBL hash function uses a constant which has a role to make the DBL hash function collision-resistant in the ideal cipher model. However, we have to instantiate a block cipher. In this paper, we show that the constant may be used as a trapdoor to help a attacker to find a collision easily. In case of 256-bit output size, we can find a collision with the complexity $2^{64}$. This is a gap between the security of the DBL hash function in the ideal cipher model and the security of the DBL hash function based on any block cipher.

Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Keywords: Hash Function Collision Attack Block Cipher Double Block Length Hash Function Constant Trapdoor.
Contact author(s): pointchang @ gmail com
History: 2006-12-24: received
Short URL: https://ia.cr/2006/481
License: CC BY

BibTeX

@misc{cryptoeprint:2006/481,
      author = {Donghoon Chang},
      title = {A Practical Limit of Security Proof in the Ideal Cipher Model : Possibility of Using the Constant As a Trapdoor In Several Double Block Length Hash Functions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2006/481},
      year = {2006},
      url = {https://eprint.iacr.org/2006/481}
}